{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,1]],"date-time":"2026-07-01T03:43:05Z","timestamp":1782877385060,"version":"3.54.5"},"reference-count":47,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2021,12,27]],"date-time":"2021-12-27T00:00:00Z","timestamp":1640563200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Molecules"],"abstract":"<jats:p>The parasite Trypanosoma brucei (T. brucei) is responsible for human African trypanosomiasis (HAT) and the cattle disease \u201cNagana\u201d which to this day cause severe medical and socio-economic issues for the affected areas in Africa. So far, most of the available treatment options are accompanied by harmful side effects and are constantly challenged by newly emerging drug resistances. Since trypanosomatids are auxotrophic for folate, their pteridine metabolism provides a promising target for an innovative chemotherapeutic treatment. They are equipped with a unique corresponding enzyme system consisting of the bifunctional dihydrofolate reductase-thymidylate synthase (TbDHFR-TS) and the pteridine reductase 1 (TbPTR1). Previously, gene knockout experiments with PTR1 null mutants have underlined the importance of these enzymes for parasite survival. In a search for new chemical entities with a dual inhibitory activity against the TbPTR1 and TbDHFR, a multi-step in silico procedure was employed to pre-select promising candidates against the targeted enzymes from a natural product database. Among others, the sesquiterpene lactones (STLs) cynaropicrin and cnicin were identified as in silico hits. Consequently, an in-house database of 118 STLs was submitted to an in silico screening yielding 29 further virtual hits. Ten STLs were subsequently tested against the target enzymes in vitro in a spectrophotometric inhibition assay. Five compounds displayed an inhibition over 50% against TbPTR1 as well as three compounds against TbDHFR. Cynaropicrin turned out to be the most interesting hit since it inhibited both TbPTR1 and TbDHFR, reaching IC50 values of 12.4 \u00b5M and 7.1 \u00b5M, respectively.<\/jats:p>","DOI":"10.3390\/molecules27010149","type":"journal-article","created":{"date-parts":[[2021,12,28]],"date-time":"2021-12-28T01:20:43Z","timestamp":1640654443000},"page":"149","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":11,"title":["Sesquiterpene Lactones with Dual Inhibitory Activity against the Trypanosoma brucei Pteridine Reductase 1 and Dihydrofolate Reductase"],"prefix":"10.3390","volume":"27","author":[{"given":"Katharina","family":"Possart","sequence":"first","affiliation":[{"name":"Institute of Pharmaceutical Biology and Phytochemistry (IPBP), University of Muenster, PharmaCampus, Corrensstrasse 48, D-48149 Muenster, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Fabian C.","family":"Herrmann","sequence":"additional","affiliation":[{"name":"Institute of Pharmaceutical Biology and Phytochemistry (IPBP), University of Muenster, PharmaCampus, Corrensstrasse 48, D-48149 Muenster, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0666-2676","authenticated-orcid":false,"given":"Joachim","family":"Jose","sequence":"additional","affiliation":[{"name":"Institute of Pharmaceutical and Medicinal Chemistry, University of Muenster, PharmaCampus, Corrensstrasse 48, D-48149 Muenster, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0443-5402","authenticated-orcid":false,"given":"Maria P.","family":"Costi","sequence":"additional","affiliation":[{"name":"Department of Life Sciences, University of Modena and Reggio Emilia, Via G. Campi 103, 41125 Modena, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2634-9705","authenticated-orcid":false,"given":"Thomas J.","family":"Schmidt","sequence":"additional","affiliation":[{"name":"Institute of Pharmaceutical Biology and Phytochemistry (IPBP), University of Muenster, PharmaCampus, Corrensstrasse 48, D-48149 Muenster, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2021,12,27]]},"reference":[{"key":"ref_1","unstructured":"(2021, September 22). Neglected Tropical Diseases-Global. Available online: https:\/\/www.who.int\/health-topics\/neglected-tropical-diseases#tab=tab_1."},{"key":"ref_2","unstructured":"(2021, December 22). Neglected Tropical Diseases. Available online: https:\/\/www.who.int\/health-topics\/neglected-tropical-diseases#tab=tab_2."},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Mitra, A.K., and Mawson, A.R. (2017). Neglected Tropical Diseases: Epidemiology and Global Burden. Trop. Med. Infect. Dis., 2.","DOI":"10.3390\/tropicalmed2030036"},{"key":"ref_4","unstructured":"(2021, September 08). Trypanosomiasis, Human African (Sleeping Sickness). Available online: https:\/\/www.who.int\/news-room\/fact-sheets\/detail\/trypanosomiasis-human-african-(sleeping-sickness)."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"215","DOI":"10.1007\/s40265-019-1051-6","article-title":"Fexinidazole: First Global Approval","volume":"79","author":"Deeks","year":"2019","journal-title":"Drugs"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"583262","DOI":"10.1155\/2015\/583262","article-title":"Overview of the Diagnostic Methods Used in the Field for Human African Trypanosomiasis: What Could Change in the Next Years?","volume":"2015","author":"Bonnet","year":"2015","journal-title":"BioMed Res. Int."},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Camara, M., Ouattara, E., Duvignaud, A., Migliani, R., Camara, O., Leno, M., Solano, P., Bucheton, B., Camara, M., and Malvy, D. (2017). Impact of the Ebola outbreak on Trypanosoma brucei gambiense infection medical activities in coastal Guinea, 2014\u20132015: A retrospective analysis from the Guinean national Human African Trypanosomiasis control program. PLoS Negl. Trop. Dis., 11.","DOI":"10.1371\/journal.pntd.0006060"},{"key":"ref_8","unstructured":"Relman, D.A., and Choffnes, E.R. (2011). The causes and Impacts of Neglected Tropical and Zoonotic Diseases: Opportunities for Integrated Intervention Strategies, Workshop Summary, National Academies Press."},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Lucius, R., Loos-Frank, B., and Lane, R.P. (2018). Biologie Von Parasiten, Springer Spektrum. [3rd ed.].","DOI":"10.1007\/978-3-662-54862-2"},{"key":"ref_10","first-page":"257","article-title":"Epidemiology of human African trypanosomiasis","volume":"6","author":"Franco","year":"2014","journal-title":"CLEP"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"10429","DOI":"10.1074\/jbc.M110.209593","article-title":"Dissecting the metabolic roles of pteridine reductase 1 in Trypanosoma brucei and Leishmania major","volume":"286","author":"Ong","year":"2011","journal-title":"J. Biol. Chem."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"24768","DOI":"10.1074\/jbc.M116.750422","article-title":"The Role of Folate Transport in Antifolate Drug Action in Trypanosoma brucei","volume":"291","author":"Dewar","year":"2016","journal-title":"J. Biol. Chem."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"186","DOI":"10.1038\/nsb0394-186","article-title":"Structure of and kinetic channelling in bifunctional dihydrofolate reductase-thymidylate synthase","volume":"1","author":"Knighton","year":"1994","journal-title":"Nat. Struct. Biol."},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Gibson, M.W., Dewar, S., Ong, H.B., Sienkiewicz, N., and Fairlamb, A.H. (2016). Trypanosoma brucei DHFR-TS Revisited: Characterisation of a Bifunctional and Highly Unstable Recombinant Dihydrofolate Reductase-Thymidylate Synthase. PLoS Negl. Trop. Dis., 10.","DOI":"10.1371\/journal.pntd.0004714"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"1448","DOI":"10.1073\/pnas.0704384105","article-title":"Discovery of potent pteridine reductase inhibitors to guide antiparasite drug development","volume":"105","author":"Cavazzuti","year":"2008","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"905","DOI":"10.1021\/cb200124r","article-title":"Trypanosomal dihydrofolate reductase reveals natural antifolate resistance","volume":"6","author":"Vanichtanankul","year":"2011","journal-title":"ACS Chem. Biol."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"13883","DOI":"10.1074\/jbc.272.21.13883","article-title":"The roles of pteridine reductase 1 and dihydrofolate reductase-thymidylate synthase in pteridine metabolism in the protozoan parasite Leishmania major","volume":"272","author":"Nare","year":"1997","journal-title":"J. Biol. Chem."},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Kimuda, M.P., Laming, D., Hoppe, H.C., and Tastan Bishop, \u00d6. (2019). Identification of Novel Potential Inhibitors of Pteridine Reductase 1 in Trypanosoma brucei via Computational Structure-Based Approaches and in Vitro Inhibition Assays. Molecules, 24.","DOI":"10.3390\/molecules24010142"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"e0034820","DOI":"10.1128\/CMR.00348-20","article-title":"Natural-Product-Based Solutions for Tropical Infectious Diseases","volume":"34","author":"Adegboye","year":"2021","journal-title":"Clin. Microbiol. Rev."},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Moujir, L., Callies, O., Sousa, P.M.C., Sharopov, F., and Seca, A.M.L. (2020). Applications of Sesquiterpene Lactones: A Review of Some Potential Success Cases. Appl. Sci., 10.","DOI":"10.3390\/app10093001"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"325","DOI":"10.1128\/AAC.01263-13","article-title":"In Silico prediction and experimental evaluation of furanoheliangolide sesquiterpene lactones as potent agents against Trypanosoma brucei rhodesiense","volume":"58","author":"Schmidt","year":"2014","journal-title":"Antimicrob. Agents Chemother."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"2062","DOI":"10.3390\/molecules14062062","article-title":"Quantitative structure--antiprotozoal activity relationships of sesquiterpene lactones","volume":"14","author":"Schmidt","year":"2009","journal-title":"Molecules"},{"key":"ref_23","unstructured":"Herrmann, F.C. (2016). In Silico-Identifikation Und in Vitro-Evaluation Nat\u00fcrlicher Inhibitoren Diverser Therapierelevanter Zielenzyme Von Humanpathogenen Eukaryoten der Gattungen Trypanosoma, Leishmania und Plasmodium. [Ph.D. Thesis, Westf\u00e4lische Wilhelms-Universit\u00e4t]."},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Herrmann, F.C., Sivakumar, N., Jose, J., Costi, M.P., Pozzi, C., and Schmidt, T.J. (2017). In Silico Identification and In Vitro Evaluation of Natural Inhibitors of Leishmania major Pteridine Reductase, I. Molecules, 22.","DOI":"10.3390\/molecules22122166"},{"key":"ref_25","unstructured":"Sambrook, J., and Russell, D.W. (2001). Molecular Cloning: A Laboratory Manual, Cold Spring Harbor Laboratory Press. [3rd ed.]."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"1781","DOI":"10.1002\/slct.201703063","article-title":"Ionic Liquid-Assisted Extraction and Isolation of Cynaropicrin and Cnicin from Artichoke and Blessed thistle","volume":"3","author":"Mizuno","year":"2018","journal-title":"ChemistrySelect"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"225","DOI":"10.1055\/s-0031-1280371","article-title":"9\u03b2-hydroxyparthenolide esters from Inula montbretiana and their antiprotozoal activity","volume":"78","author":"Kaiser","year":"2012","journal-title":"Planta Med."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"124","DOI":"10.1021\/acs.jnatprod.7b00747","article-title":"Antiprotozoal Sesquiterpene Lactones and Other Constituents from Tarchonanthus camphoratus and Schkuhria pinnata","volume":"81","author":"Kimani","year":"2018","journal-title":"J. Nat. Prod."},{"key":"ref_29","unstructured":"Nogueira Da Silva, M. (2016). The Use of Chemometric and Chemoinformatic Tools for Identification and Targeted Isolation of Compounds from Asteraceae with Antiprotozoal Activity. [Ph.D. Thesis, Westf\u00e4lische Wilhelms-Universit\u00e4t]."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"2176","DOI":"10.2174\/092986712800229087","article-title":"The potential of secondary metabolites from plants as drugs or leads against protozoan neglected diseases-part II","volume":"19","author":"Schmidt","year":"2012","journal-title":"Curr. Med. Chem."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"2128","DOI":"10.2174\/092986712800229023","article-title":"The potential of secondary metabolites from plants as drugs or leads against protozoan neglected diseases-part I","volume":"19","author":"Schmidt","year":"2012","journal-title":"Curr. Med. Chem."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"750","DOI":"10.1055\/s-2002-33799","article-title":"Anti-trypanosomal activity of helenalin and some structurally related sesquiterpene lactones","volume":"68","author":"Schmidt","year":"2002","journal-title":"Planta Med."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"10546","DOI":"10.3390\/molecules190710546","article-title":"Hologram QSAR studies of antiprotozoal activities of sesquiterpene lactones","volume":"19","author":"Trossini","year":"2014","journal-title":"Molecules"},{"key":"ref_34","doi-asserted-by":"crossref","unstructured":"Kimani, N.M., Matasyoh, J.C., Kaiser, M., Nogueira, M.S., Trossini, G.H.G., and Schmidt, T.J. (2018). Complementary Quantitative Structure\u2014Activity Relationship Models for the Antitrypanosomal Activity of Sesquiterpene Lactones. Int. J. Mol. Sci., 19.","DOI":"10.3390\/ijms19123721"},{"key":"ref_35","first-page":"577","article-title":"Toxic activities of sesquiterpene lactones: Structural and biochemical aspects","volume":"3","author":"Schmidt","year":"1999","journal-title":"Curr. Org. Chem."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"553","DOI":"10.1055\/s-0031-1298241","article-title":"Cynaropicrin: The first plant natural product with in vivo activity against Trypanosoma brucei","volume":"78","author":"Zimmermann","year":"2012","journal-title":"Planta Med."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"7202","DOI":"10.1016\/j.bmc.2013.08.052","article-title":"Cynaropicrin targets the trypanothione redox system in Trypanosoma brucei","volume":"21","author":"Zimmermann","year":"2013","journal-title":"Bioorg. Med. Chem."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"490","DOI":"10.1002\/(SICI)1096-987X(199604)17:5\/6<490::AID-JCC1>3.0.CO;2-P","article-title":"Merck molecular force field. I. Basis, form, scope, parameterization, and performance of MMFF94","volume":"17","author":"Halgren","year":"1996","journal-title":"J. Comput. Chem."},{"key":"ref_39","unstructured":"(2021, September 01). RCSB Protein Data Bank: Homepage. Available online: https:\/\/www.rcsb.org\/."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"1334","DOI":"10.1107\/S0907444910040886","article-title":"High resolution structure of TbPTR1 in complex with Pemetrexed","volume":"66","author":"Dawson","year":"2010","journal-title":"Acta Crystallogr. Sect. D Struct. Biol."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"1334","DOI":"10.1107\/S0907444910040886","article-title":"Structure of PTR1 from Trypanosoma brucei in ternary complex with 2,4-diamino-5-[2-(2,5-dimethoxyphenyl)ethyl]thieno[2,3-d]-pyrimidine and NADP+","volume":"66","author":"Dawson","year":"2010","journal-title":"Acta Crystallogr. Sect. D Struct. Biol."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"6479","DOI":"10.1021\/jm500483b","article-title":"Crystal structure of pteridine reductase 1 (PTR1) from Trypanosoma brucei in ternary complex with cofactor and inhibitor","volume":"57","author":"Khalaf","year":"2014","journal-title":"J. Med. Chem."},{"key":"ref_43","first-page":"7598","article-title":"Trypanosoma brucei PTR1 in complex with cofactor and inhibitor NMT-H024 (compound 2)","volume":"59","author":"Landi","year":"2016","journal-title":"J. Med. Chem."},{"key":"ref_44","doi-asserted-by":"crossref","unstructured":"Vanichtanankul, J., Taweechai, S., Yuvaniyama, J., Vilaivan, T., Chitnumsub, P., Kamchonwongpaisan, S., and Yuthavong, Y. (2011). Trypanosoma brucei dihydrofolate reductase pyrimethamine complex. ACS Chem. Biol., 6.","DOI":"10.2210\/pdb3qfx\/pdb"},{"key":"ref_45","doi-asserted-by":"crossref","unstructured":"Vanichtanankul, J., Taweechai, S., Yuvaniyama, J., Vilaivan, T., Chitnumsub, P., Kamchonwongpaisan, S., and Yuthavong, Y. (2011). Trypanosoma brucei dihydrofolate reductase (TbDHFR) in complex with WR99210. ACS Chem. Biol., 6.","DOI":"10.2210\/pdb3rg9\/pdb"},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"3","DOI":"10.1016\/S0169-409X(00)00129-0","article-title":"Experimental and computational approaches to estimate solubility and permeability in drug discovery and development settings","volume":"46","author":"Lipinski","year":"2001","journal-title":"Adv. Drug. Deliv. Rev."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"5471","DOI":"10.1007\/s00253-014-5551-8","article-title":"Escherichia coli kduD encodes an oxidoreductase that converts both sugar and steroid substrates","volume":"98","author":"Tubeleviciute","year":"2014","journal-title":"Appl. Microbiol. Biotechnol."}],"container-title":["Molecules"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1420-3049\/27\/1\/149\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T07:54:26Z","timestamp":1760169266000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1420-3049\/27\/1\/149"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,12,27]]},"references-count":47,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2022,1]]}},"alternative-id":["molecules27010149"],"URL":"https:\/\/doi.org\/10.3390\/molecules27010149","relation":{},"ISSN":["1420-3049"],"issn-type":[{"value":"1420-3049","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,12,27]]}}}